Posted
by
Zonkon Saturday October 28, 2006 @07:22AM
from the happy-cjsuiebz dept.

An anonymous reader writes "Public key crypto turned 30 last night, and the biggest names in crypto turned out to celebrate at an event hosted at the Computer History Museum. Voltage Security teamed with RSA to bring together some of the most famous cryptographers of yesterday (Whitfield Diffie and Martin Hellman) and today (Dan Boneh), along with luminaries Ray Ozzie, Brian Snow, and Jim Bidzos. From the ZDNet article: 'NYT reporter John Markoff, who has covered Silicon Valley for 30 years, was master of ceremonies, and started off by saying that no technology has had a more profound impact than cryptography, and that public-key cryptography has been underappreciated for its role in the Internet. Without public key cryptography, ecommerce would be an idea as opposed to an enabler of billions of daily transactions.' You can view the podcast and pictures of the event at the Voltage Security site.."

So, is this the 30th anniversary of the public discovery of public key cryptography or the 30th anniversary of the official (publicised) date on which Clifford Cox and co secretly discovered it for a very non-public organisation?

Wikipedia says that Diffie and Hellman published their work in 1976, and that the earlier secret work was going on in the early 70s. So it looks like they're talking about the public discovery, assuming both that Wikipedia is correct and that I can add small numbers in my head accurately.

Yes, public key cryptography was first discovered by Clifford Cox (of the British GCHQ) in 1973 (in contrast, RSA was invented in 1977 according to wikipedia). But, because Cox' research was kept secret until long after RSA had become mainstream it did nothing to advance cryptographic research. Same applies to the first computer - We now know that Colossus was the first computer [1] and not Eniac, but since Eniac was not kept secret it literally became the grandfather of all computers in spite of Colossus;

I was a math undergrad interested in large prime numbers and numerical computing when the first hints on what RS&A were doing came out in Scientific American. At that time I had only 3 years programming experience and it was a big thrill to get a public key crypto email system working (first in Pascal on a DEC-20) but I only distributed it to a small group as the university was not yet on the Internet.

I told the story to PZ at a conference about 8 years ago and we had a good laugh wondering how things might have developed differently had that program been distributed on Usenet by someone outside the USA!

Historians of science will certainly spend time sorting out the various
claims. David Kahn, the author of the best selling history The
Codebreakers, said that he recently asked the National Security Agency
to declassify some documents so he could write the proper history of
public key cryptography. He said an NSA staff member told him, "I've
spoken to the guys who did this, but they don't want to be interviewed
now." This suggests that the NSA also may have discovered public-key
systems or had a hand in exploring them. Kahn hopes that the NSA will
follow in Britain's lead so an accurate history can be written.

It is likely that the NSA discovered public key Cryptography in the late 60's or early 70's. Public Key Cryptography may be as old as 40 years old at this point, but without clarification from the NSA, we will never be certain.

When I was at school we saw a film on crytography saying a British mathematician had come up with the idea before it had been published to the public by a fairy long time. It was for government use though, and so very classified.Can anyone back this up? I definitely remember watching the film, and feeling very sorry for the poor bloke who got basically nothing for his idea.

If PKC isn't as important as you say it is, then why do we have a multibillion dollar agency (which hires the most brilliant mathematicians and computer scientists in the country) almost entirely devoted to cryptography? Plus, it's illegal for us to use certain key sizes because the NSA considers it to be a weapon!PKC and other forms of cryptography are extremely important and vital to the success of NATIONS. Plus, imagine how hard it would be to communicate over the Internet without PKC, you'd have to sync

The real "missed opportunitity", if you think of it as such, was from the middle of the last century in Bletchley Park and elsewhere. That's when cryptography and computer science started to come together.

A lot of people seem to forget that one of the first really widespread products that end users in corporations used that fully integrated public/private key encryption was Lotus Notes. I started using it in 1991, but I believe as early as 1989 it was functionally part of the product.

Sure, others used it before then, but in terms of a widely used corporate end user audience, it was (and still is to some extent) unique.

Yes, you may now rag on Notes if you like -- of course, keep in mind it remains the only real solution for a major corporation that by public key authentication and encryption by default, has a fully functional smtp mta built in, handles the front end needs of end users well enough for salespeople (not like a typical pop or imap client) and of course, fully supports linux as a server platform (and within a few months as a client platform as well).:-)

I don't like to take away from their excellent work, but it is possible, though inconvenient, to do private-key crypto for such things.

Your bank, for example, would need to [paper] mail you a private key to type into your machine (or give you a thumbdrive with it, whatever you like). Inconvenient, yes; you'd need a new key for each company you interact with. Probably it would encourage a few monopolies (amazon and eBay) to dominate, since you'd only need to interact with them by paper once. But not impossible.

For most transactions, you only really need a private key shared with your credit card provider.Merchants could do the same and the problem is mostly solved without a PKI. We still might need to do this anyway.One time tokens anyone?

This would not work at all, because someone could easily intercept your mail at the mailbox, post office, etc. Sending plaintext by snail mail is just as secure as sending plaintext over the net, i.e. its not.

For this to be secure you would probably have to go and pick up your private key at the bank yourself.

That's not exactly how it works, there are two keys one private (bank) and one public (customer). The public key does not need to be a secret since it can't be used to decrypt the message only encrypt it. The "one way" math function is based on the difficulty of factorising large numbers (thus all the interest in large primes). Having a one way function is why PKE is different to other forms of encryption, it means you don't have the problem of distributing a single secret key.

I've had a public key for a few years and have cross-signed keys of a few people I know, but most do not encrypt or even sign their emails despite knowing the insecurities of email. I'm surprised that it is not used more commercially, but I have never had a signed or encrypted email at work and that often involves commercially sensitive information.

Could it be that encryption is still to complex for most people?

I will continue to encrypt emails to those I know can handle it and will sign others.

Can you please point me to either a free email client that is easy enough to use and has a decent interface? Or a plugin for an existting one, that supports this? I'd be very interested in doing this (although I don't know anyone who has the technical capacity to figure out how to read it that wouldn't just ask me to send it unencrypted)

That list looks a bit outdated. Netscape mail, but no thunderbird?
At this stage i'm using Mac OS X Mail as my mail client, but the GPGMail site says: "GPGMail is a complete hack, relying on Mail's private internal API. Use it at your own risks!"
From the number of times ive almost lost large portions of my email because of Mail's less-than-ideal database sytem, i'd rather not risk it. Plus the screenshots are obviously from like OSX.1 o2 X.2. Although the last updated date is fairly recent. I might r

The biggest issue is that people simply really just don't care. When I try to advocate this stuff to laymen, by far the most common comment I hear is "So what if someone reads my email?" Most people don't think email privacy is worth protecting. Yes, even despite the news stories in the last few years (i.e. the government really is reading your email; it's not just a paranoid crackpot theory anymore).

Another issue is something that has actually gotten worse in the last 10 years. Webmail is very popular. It's nearly impossible to do email encryption correcting using webmail instead of "real" (e.g. POP or IMAP) mail. You either have to trust a foreign system with your keys, or you have to have so much non-web-intelligence running inside the web browser (e.g. a Java applet or something) that it isn't really webmail anymore. And even if you make it sophisticated enough to run on the web browser, you lose one of the major advantages of webmail: checking your email from anywhere, including untrusted machines. (The only way to do it then, is for the user to do the crypto inside their head instead of using a computer.) It's a mess and it just can't be done right. As long as people want webmail, as long as they see it as a good thing instead of a bad thing, they can't have good encryption. (Well, unless they are the admin of the web server. e.g. One person at Google could conceivably use gmail as a secure webmail system.;-)

Hopefully in 30 years from now, we will live in a world where encrypting email, IM conversations, personal documents and anything else that you would rather not be public becomes something everyday people do and not something that "geeks" do.Hopefully we see a world where the major email clients (including Thunderbird/Seamonkey) come with easy to use email encryption out of the box.Hopefully we see a world where your communications and data are safe from people you would rather didnt see them (black-hat hac

I suspect that what might work without overhauling SMTP completely (and this is very much a blue sky idea).

1a) Mail servers that start caching SSH-style public keys for servers that they talk to. Then encrypt the transport between the two servers. There are definitely MITM attacks that could be mounted, but the outbound MTA might simply keep track of key-changed events in the log files. Let the admins worry about it, if they do.

1b) IPSec with opportunistic encryption for encrypting the transport. Ma

You dont need to make it that complex.Essentially, if the recipiant supports encryption, the recipiants public key is pulled from a key server. Then, the email client encrypts it using something similar to PGP or GPG. Something thats standard enough that anyone can implement it.At the other end, it is decrypted by the mail client using the recipiants private key.All that the servers in the middle see is an encrypted email (same as they would see if you encrypted an email right now with PGP or GPG or whateve

For all the legitimate uses of public-key cryptography, I seem to think that most uses of it are bad. I see the Xbox, Xbox 360, Vista, Leopard and Tivo using public-key cryptography for nothing but removing the authority of computer owners to decide what software they run on their computer. I see VeriSign getting rich off the VeriSign Tax.

I personally think that it would be far better to make use of shared-secret systems for when you need communication security, like logging onto banks. The solution to phishing is clearly to use a shared secret system, because things like IE7's anti-phishing filtering can be worked around. SRP6 is great, but unfortunately that is based on public-key technology (though doesn't actually involve a public key, like Diffie-Hellman).

I hope that someday it is proven that public-key cryptography cannot be securely attached to an NP-complete problem, and that either a fast discrete logarithm algorithm (*) is found or quantum computers take off.

(*) A fast solution to the discrete logarithm problem implies a fast solution to integer factorization.

Without public key cryptography, ecommerce would be an idea as opposed to an enabler of billions of daily transactions.

Hardly. Phone conversations are not encrypted and can be/are intercepted, yet phone commerce is commonplace. Even in-person credit card purchases are hardly secure and there are a number of websites that do e-commerce without encryption. Without public key cryptography, more attention would be paid to security of the path between your ISP and the vendor. Websites could also have you set up username and password over a more secure channel and then use plain symmetrical encryption for the actual purchase.

Without public key cryptography, ecommerce would be an idea as opposed to an enabler of billions of daily transactions.

And without the patent on public-key encryption that covered not just the method but the very idea of it, we might all have secured communications by now. But instead we are not much further ahead except for ssh which at least helps network admins.

I just have a hard time cheering for RSA which did nothing other than patent a mathematical formula discovered by multiple people and prevent it's dfree use in America and other countries that allow software patents.

I was using PGP back in the early 90's and was frustrated that it's use was hamstrung by the patent and US laws on exporting encryption software. What a waste.